//导入express包
const express = require("express");

//创建服务器实例
const app = express();
const port = 3000;

//后端路由
app.get("/", (req, res) => {
  res.send("Hello World!");
});

//设置监听端口，监听成功的回调
app.listen(port, () => {
  console.log(`Example app listening on port ${port}`);
});
